Fluidized-bed membrane reactors

Experiments were conducted at the University of Magdeburg to examine the partial oxidation of ethane to ethylene by dosing oxygen into the fluidized bed of porous catalysts using immersed sintered metal and ceramic membranes. These studies were related to a DFG (German Research Association) research group (DFG-Nr. FOR 447/1-1) Membrane supported reaction engineering in the subproject Fluidized-bed membrane reactor . 

Adds, A. Lim, C. Grace, J. The Fluidized Bed Membrane Reactor System A Pilot-Scale Experimental Study Chemical Engineering Science 49, No. 24B (1994) 5833-5843. 

The beneficial effects of a fluidized-bed membrane reactor on methane conversion and hydrogen yield can be optimized by systematically varying the operating parameters such as catalyst amount, membrane area for permeation, rate of heat supply, and reactor bed height and bed volume. A hydrogen yield of 3.70 and an accompanying methane conversion of 92% can be attained at a relatively moderate temperature of 733 C which... 

While most of the membrane reactor studies on ethylbenzene dehydrogenation employ fixed-bed membrane reactors, Abdalla and Elnashaie [1995] evaluated the concept of a fluidized-bed membrane reactor through modeling. Since hydrogen is released from the reaction, a palladium-based membrane can be used for this application. 

Adhs. A.M., 1994, A Fluidized Bed Membrane Reactor for Steam Methane Reforming Experimental Verification and Model Validation, Ph.D. dissertation, Univ. of British Columbia, Vancouver, Canada. 

Comparison of performance of fluidized bed membrane reactor (FBMR), fluidized bed reactor (FBR) and continuous stirred tank reactor (CSTR)... 

Horizontal versus vertical membrane tubes or modules. Two general types of fluidized-bed membrane reactors have been tested. The first type places the membrane elements or modules perpendicular to the general direction of the fluidizing reaction gases (see Figures 10.14a and 10.14b). In the second type of FBMR, the membrane elements or modules are essentially parallel to the fluid flow direction inside the reactor, as schematically shown in Figure 11.50. It appears that the vertical type exhibits more advantages for practical implementation. 

Figure 11.50 Schematic diagram of a fluidized bed membrane reactor with vertical membrane elements [Adrisetal.. 1994b]...

Finally, possible causes for deactivation of catalytic membranes are described and severad aspects of regenerating catalytic membrane reactors are discussed. A variety of membrane reactor configurations are mentioned and some unique membrane reactor designs such as double spiral-plate or spiral-tube reactor, fuel cell unit, crossflow dualcompartment reactor, hollow-fiber reactor and fluidized-bed membrane reactor are reviewed. 

Abashar, M. (2004). Coupling of steam and dry reforming of methane in catalytic fluidized bed membrane reactors, hit. ]. Hydrogen Energy 29, 799-808. 

Rakib, M.A. and Alhumaizi, K.I. Modeling of a fluidized bed membrane reactor for the steam reforming of methane Advantages of oxygen addition for favorable hydrogen production. Energy Fuels, 2005, 19, 2129. 

H.M. Adris, C.J. Lim and J.R. Grace, The fluidized bed membrane reactor system A pilot-scale experimental study. Paper presented at ISCRE 13, September 1994, Baltimore, MD, USA. 

CMRH catalytic membrane reactor high conversion FBCMR fluidized bed catalytic membrane reactor FBMR fluidized bed membrane reactor... 

Packed Bed Catalytic Membrane Reactor Fluidized Bed Membrane Reactor Fluidized Bed Catalytic Membrane Reactor Catalytic Non-permselective Membrane Reactor Supported Liquid-phase Catalytic Membrane Reactor-Separator... 

Recently, the fluidized bed membrane reactor (FBMR) has also been examined from the scale-up and practical points of view. Key factors affecting the performance of a commercial FBMR were analysed and compared to corresponding factors in the PBMR. Challenges to the commercial viability of the FBMR were identified. A very important design parameter was determined to be the distribution of membrane area between the dense bed and the dilute phase. Key areas for commercial viability were mechanical stability of reactor internals, the durability of the membrane material, and the effect of gas withdrawal on fluidization. Thermal uniformity was identified as an advantageous property of the FBMR. 

Ostrowski T, Giroir-Fendler A, Mirodatos C, Mleczko L. Comparative study of the partial oxidation of methane to synthesis gas in fixed-bed and fluidized-bed membrane reactors Part II— Development of membranes and catalytic measurements. Catal Today 1998 40(2-3) 191-200. 

A new development in this field is the use of fluidized-bed systems instead of a packed bed. For this purpose, steam reforming of methane has been used as a model reaction [88]. From experimental and theoretical work it can be concluded that fluidized-bed membrane reactors potentially represent a promising system as problems of heat transfer and equilibrium limitations can be addressed simultaneously. As one of the major problems encountered is to provide sufficient membrane area per volume, possible solutions are the use of hollow-fiber systems [13] or membranes based on microsystem technology. In Fig. 5.7 an indication can be obtained for the potential of this approach to enlarge the effective membrane area versus the superficial area of the wafers used [89]. 

Mahecha-Botero A, Boyd T, Gulamhusein A, Comyn N, l.im CJ, Grace JR, Shirasaki Y, Yasuda I (2008) Pure hydrogen generation in a fluidized-bed membrane reactor experimental findings. Chem Eng Sci 63 2752-2762... 

Gallucci F, Van Sint Annaland M, Kuipers JAM (2008) Autothermal reforming of methane with integrated CO2 capture in a novel fluidized bed membrane reactor. Part 1 experimental demonstration. Top Catal 51 133-145... 

Different types of membrane reactors for hydrogen production have been proposed in the literature. Most of the previous work has been performed in packed bed membrane reactors (PBMRs) however, there is an increasing interest in novel configurations such as fluidized bed membrane reactors (FBMRs) and membrane micro-reactors (MMRs), especially because better heat management and decreased mass transfer limitations can be obtained in these novel reactor configurations. 

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